1. Field of the Invention
The present invention relates to archery bow sighting devices. More specifically, the present invention pertains to an automatically adjusting archery sight device that responds to input from an imbedded laser range finding device for tracking mobile and long-distance targets. A singular sighting pin is provided along a motorized track. Input from the laser range finder updates the sighting pin elevation along its track and notifies the user of the target distance through a backward facing digital display. Input from the laser range finder and corresponding output to the sighting pin is controlled by an internal electronic circuit, which interpolates between preset distances determined when calibrating a given archery bow. Power for the device is fed from a battery pack tethered to the user to reduce bow weight and improve accuracy.
2. Description of the Prior Art
Archery hunting and long-distance archery aiming is a difficult task, even for seasoned archers. Arrow speed and adjustments for elevation drop over a long distance are difficult measures to estimate accurately. Incorrect aiming of an arrow upon release can lead to several unwanted consequences, including missing a target, wounding but not disabling a potential target animal, or finally hitting an unintended target altogether. None of these situations is desirable, especially considering the diligence and time required to locate a potential target.
Contemporary bow sights utilize a series of illuminated sighting pins vertically stacked within a sighting window to provide a user with the ability to adjust his or her aim for a calibrated distance. Each pin represents a different yardage marker, allowing the user to place a desired distance pin on the target while viewing through the sighting window. The pin provides a bow elevation adjustment, changing the trajectory of the arrow to account for longer or shorter distances to the target. These devices are useful, but are often cluttered with too much information. The sighting pins obscure a user's view of the target, while the distance is not always automatically calculated. The archer must estimate the distance and illuminate a pin that corresponds to that distance. This introduces two sources of error, one involving the distance estimation, and the second involving the user's memory with regard to which pin corresponds to a given distance.
Bow sights have been described in the art that incorporate laser range finding means coupled with contemporary archery sights. The range finding generally accompanies an electronic device that illuminates a given pin based on the target distance, or alternatively provides the user with a distance to manually adjust the sighting pins. While this improves the method of determining distance to a target and removes estimation errors, the use of multiple sighting pins or requiring a user to manually choose a calibrated pin based on a distance still involves a level of error that can be further eliminated with the present invention. Improper aiming of the range finder means while measuring the distance to target can also present errors. If the bow is aimed from a different position or orientation than that of the firing position, or if the archer is positioned in a different stance when utilizing the range finding means, the distance to target may be in error. The distance prior to release may be different than the distance determined by the range finder. This error is also addressed in the present invention, wherein a laser range finder aiming reticle and peep sight are provided that allow accurate alignment of the bow to the target in a firing position, and accurate distance determination thereof.
Devices have also been disclosed in the prior art that describe combination laser sighting devices and adjustable sighting means. These include mechanically motorized sights, illuminating digital screens and optical displays that show a target and an arrow impact location given its trajectory and release velocity. These devices share a common drawback in that their laser sighting means is not guaranteed to be aligned with the arrow trajectory prior to release. An individual sighting pin is also not provided that automatically updates its position based on laser range finder input. The present invention utilizes this input, and input from the user when the bow is calibrated, to interpolate between calibrated distances and determine the most accurate sighting pin position for a given distance, determined by the laser range finder.
Patents have been published that disclose similar bow mounted sighting devices. These include both automatic and non-automatically adjusting sights based on distance to a target. U.S. Pat. No. 3,766,656 to Westphal is one such device, wherein an adjustable sight pin is provided when the bow is drawn. An electrical switch accessible by the archer energizes a motor that drives a sighting pin along a screw device, updating its position based on distance and anticipated arrow trajectory. The movement of the sighting pin is manually controlled by the user during the aiming process, without any distance measurement means or automatic adjustment resulting therefrom. This device is useful for updating a bow sight while the bow is drawn, but it relies heavily on user ability and judgment to produce an accurate shot.
U.S. Pat. No. 5,511,317 to Allen is a similar bow sight device in which the user may manually adjust the sight based on distance to a target. The sighting element may be displaced in height to adjust the orientation of the arrow trajectory and subsequent impact location. The adjustment is achieved by a rotary mechanism, controlled by the archer's bow hand while the string is drawn. Similar to the Westphal patent, this mechanism has no means to measure the range to target or automatically adjust the sight mechanism based on those measurements. This device similarly introduces greater risk of misjudging the distance and missing the target altogether, as opposed to the present invention, wherein distance to target is measured and the sight is automatically adjusted accordingly. The chances of wounding but not harvesting a target animal are reduced with the present invention.
U.S. Pat. No. 3,910,700 Sprandel describes a motorized sight and range finder for an archery bow, wherein a vertical slide enables vertical movement of a sight bar for placement on a target and adjustment thereof to account for distance and arrow drop. A gear train, electric motor and a series of linkages provides actuation of the sight bar along the vertical slide. As with the aforementioned patent, no laser range finding means or method of automatically adjusting the sight is provided. This sight also provides a larger, more obtrusive mechanism for adjusting the sighting pin. The linkages block the view of the archer while in use, as opposed to the internal structure and mechanisms utilized in the present invention.
U.S. Pat. No. 7,614,156 to Imig describes a bow-mounted sight unit with a range finder and optical sight. Cross-hairs on the optical sight are adjusted based on input from the laser range finder and historical data stored in a data storage unit for arrow drop over a distance for a specific bow. The cross-hairs update on the optical sight based on these inputs and control via a microprocessor, allowing compensation for long distances and accurate measurement thereof. This device provides a digital indication of the arrow impact location, as opposed to a physical sighting pin that adjusts position based on input from a laser range finding device and onboard electronics.
U.S. Pat. No. 5,575,072 to Eldridge describes an archery sight targeting and range finding device that provides a transparent window with sight markers and a digital distance indicator. The sight operates in conjunction with a range finding device to determine a distance to a destined target, automatically updates the sighting marks on the display and notifies the user of the marker distance. Imbedded electronics and a defined algorithm are provided to control the automatic adjustment of the range markers. While this device provides automatic adjustment of the sight markers, it provides it in a sufficiently different structure than the present invention. The method of aligning the sight targeting marker with the range finder marker also differs from the present invention method of aligning the range finder to the target, and the arrow trajectory thereof.
Bow and archery sight devices are well described in the art. These contain varying features and levels of sophistication with regard to range finding and sight adjustment. The present invention provides a robust, error-proof device that accurately measures a distance to a target, compensates the sighting pin for that distance, and alerts the user when ready to fire. The adjustment provides a calculated initial arrow inclination given an arrow's initial velocity and gravity over the distance to the intended target. In this way, the arrow trajectory is modified to yield a desired impact location. The present invention is a simple electromechanical device, provides a clear field of view for the user, and ensures the measured range is accurate when releasing the arrow towards a downfield target. It substantially diverges in design elements from the prior art and consequently it is clear that there is a unmet need in the art for an improvement to existing bow sight devices with automatically adjusting sight means and range finding means. In this regard the instant invention substantially fulfills these needs.